package Text2;

public class Solution {
    class ListNode{
        int val;
        ListNode next;
        ListNode() {}
        ListNode(int val) {
            this.val = val;
        }
        ListNode(int val, ListNode next) { this.val = val; this.next = next; }
    }

    public ListNode middleNode(ListNode head) {
        if(head==null){
            return null;
        }
        ListNode fast=head;
        ListNode slow=head;
        while(fast!=null&&fast.next!=null){
            fast=fast.next.next;
            slow=slow.next;
        }
        return slow;
    }
}
